1. Field of the Invention
The present invention relates to antigenic peptides which are capable of being recognised by the antibodies induced in man by retroviruses of the type HIV in accordance with the nomenclature defined in the journal Nature. The invention also relates to peptides which possess immunogenic properties or which are capable of being made immunogenic in vivo. The invention furthermore relates to applications of these peptides to the preparation of a composition for the in vitro diagnosis of AIDS in man and to the production of immunogenic compositions and vaccine compositions against the HIV viruses.
Similarly, the invention relates to the applications, with a view to the same objectives, of antibodies capable of being induced in vivo by immunogenic peptides or peptides made immunogenic, and their applications to the production of the active ingredients of drugs against certain forms of AIDS.
The invention also relates to the use of these peptides in processes for the in vitro diagnosis of infection by the viruses HIV-1 and/or HIV2, as well as the reagents or diagnostic kits for carrying out the said processes.
2. Description of the Background
A first retrovirus, named HIV-1, has been described in European Patent Application No. 138 667 of Sep. 14, 1984. A second retrovirus, named HIV-2, has been described in European Patent Application No. 239 425 of Jan. 22, 1987. These two retroviruses preferably have as their target human T4 lymphocytes and exhibit a cytopathogenic effect toward these lymphocytes.
Lysates of the HIV-1 viruses contain nuclear proteins called proteins gag and pol, which exhibit 60% homology with the corresponding gag and pol proteins of the HIV-2 viruses, and envelope proteins called env proteins which exhibit only 40% homology with the corresponding env proteins of the HIV-2 viruses.
These lysates have been used in diagnostic tests for AIDS. In order to increase the specificity of these tests, it has been proposed to substitute for the virus lysates products which do not originate from cells infected by the virus, such as synthetic peptides or peptides obtained from recombinant organisms.
Studies carried out on the different proteins of the viruses HIV-1 and HIV-2 have made it possible to distinguish peptides having identical or similar sequences to the sequences obtained in the gag proteins or in the env proteins of these viruses. Such peptides, obtained from the predominant proteins of the virus HIV-1, have been described, especially in U.S. Pat. No. 4,629,783. Peptides obtained from the predominant proteins of the virus HIV-2 have been described, especially in French Patent Application No. 2 610 632.
Peptides obtained from the gp41 and gp42 glycoproteins of the viruses HIV-1 and HIV-2, modified at their ends in order to facilitate the coupling of the said peptides to supports or carrier molecules, have likewise been proposed for diagnostic or therapeutic purposes.
Peptides made cyclic through the formation of disulphide bridges between two cysteine residues have also been proposed in European Patent Application No. 326 490.